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  • PARALLEL_REDO_LOG_CACHE Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: HADR_SYNC_COMMIT Wait TypeRelated pillar: High Availability Is It a Problem? No. The secondary replica redo model write-up lists it among the waits without performance impact, and Get Wait Statistics filters it out by default. What It Means Microsoft lists it as…

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  • PARALLEL_REDO_FLOW_CONTROL Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: HADR_SYNC_COMMIT Wait TypeRelated pillar: High Availability ⚡PARALLEL_REDO_FLOW_CONTROL is the main redo thread on a secondary unable to hand out more log, because the redo workers are not keeping up. It is one of the waits that slow redo. Judge it by…

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  • DBA Scripts: Get Log Reuse Waits

    🔧Part of the DBA-Tools Project, copy/paste SQL Server scripts and health checks.In: Storage & Capacity The One Question That Actually Matters A transaction log that won’t truncate and keeps growing, or a log backup job that suddenly can’t keep up, always comes back to the same underlying question: what is this database’s log actually waiting…

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  • PARALLEL_BACKUP_QUEUE Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: BACKUPIO and BACKUPBUFFER Wait TypesRelated pillar: Backup & Recovery Is It a Problem? No. It is bounded by how often you read backup metadata, and it was zero on our SQL Server 2025 lab. Get Wait Statistics does not filter it…

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  • PAGEIOLATCH_NL Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: PAGEIOLATCH_SH Wait TypeRelated pillar: Storage & Capacity Is It a Problem? No, and a non-zero value would itself be odd; it was zero on our SQL Server 2025 lab. Get Wait Statistics does not filter it out, so if it ranks,…

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  • PAGEIOLATCH_KP Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: PAGEIOLATCH_SH Wait TypeRelated pillar: Storage & Capacity Is It a Problem? Practically never; expect zero or close to it. It was zero on our SQL Server 2025 lab. Get Wait Statistics does not filter it out, so if it ranks, you…

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  • PAGEIOLATCH_DT Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: PAGEIOLATCH_SH Wait TypeRelated pillar: Storage & Capacity Is It a Problem? Practically never; expect zero or close to it. It was zero on our SQL Server 2025 lab. Get Wait Statistics does not filter it out, so if it ranks, you…

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  • ONDEMAND_TASK_QUEUE Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: SOS_SCHEDULER_YIELD Wait TypeRelated pillar: Performance & Troubleshooting Is It a Problem? No. Microsoft says long wait times indicate that there have been no high priority requests to process, and shouldn’t cause concern, and Get Wait Statistics filters it out by default.…

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  • OLEDB Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: ASYNC_NETWORK_IORelated pillar: Performance & Troubleshooting ⚡OLEDB is the time SQL Server spends in calls to its OLE DB provider, for linked servers and also for internal work. High totals are often not linked servers at all: DBCC CHECKDB and monitoring tools…

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  • MSQL_XP Wait Type in SQL Server

    ⏳Part of the SQL Server Wait Types Library, every wait type explained.Related deep dive: ASYNC_NETWORK_IO Wait TypeRelated pillar: Performance & Troubleshooting ⚡MSQL_XP is SQL Server waiting for an extended stored procedure, external DLL code, to finish. The wait lasts as long as the external code runs, so it tells you where the time went, not…

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